textproduct: Rapid City

KEY MESSAGES

- Weak storm system will impact the region overnight tonight through Wednesday evening. Light snow accumulations expected across northwestern SD.

- A second, stronger winter storm will impact the region Thursday afternoon through Friday with a mix of precipitation types possible and increasing potential for higher snow accumulations.

- Drier, more mild conditions arrive for the weekend into early next week.

DISCUSSION

(Tonight Through Tuesday) Issued at 1113 PM MDT Tue Mar 31 2026

Current upper air analysis depicts southwest flow over the Northern Plains with weak shortwave over CA. The southwest flow is bringing ample Pacific moisture into the region with rain/snow showers developing over western SD and northeastern WY. This precip should continue through the overnight hours into Wednesday as the upper level wave moves east over the Rockies and ejects over the central plains early Thursday. Temps overnight should be cold enough for snow, with minor accumulations expected. As temperatures warm during the day Wednesday, most areas over the western SD plains south and west of Buffalo and Faith will see precip change over to rain. Northwestern SD should remain cold enough for snow. QPF, and therefore snow totals, have trended downwards in the most recent model runs with northwestern SD seeing around 1 to 3 inches of snow. However, CAMs are still hinting at potential banded snowfall across the northwest which would result in locally higher amounts. Precip will gradually end over the region as the sfc low moves to the east.

Compact upper low will make its way onshore early Thursday, pushing eastward into the Northern Plains by early Friday. This system will be much more robust with strong Q-vector convergence and ample moisture supporting widespread precip chances over the area. Still some uncertainty on the low's track as it crosses through the region, which will impact QPF totals and evolution of precip types and thus resultant snowfall accumulations. So far, current thinking is that precip will begin Thursday afternoon with temperatures warm enough for rain across the CWA. As colder air pushes into the region late Thursday night into Friday, rain will change over to snow. Snow will continue through the day Friday before gradually tapering off Friday night. In terms of snow totals, still looking like the Black Hills, the western SD plains north of I-90, and northeastern WY will see the most snow accumulations out of this system. However, forecast confidence in exact snow totals remains low as model guidance still shows a wide spread in snowfall totals, especially across northwestern SD.

Ridge builds in over the western US for the weekend, putting the Northern Plains under northwest flow. Temperatures will warm through the weekend with mild and mostly dry weather making a return to the region through early next week.

AVIATION

(For the 12Z TAFS Through 12Z Thursday Morning) Issued At 522 AM MDT Wed Apr 1 2026

A disturbance will move from west/southwest to north/northeast today. It will spread a broken precipitation shield into the region, especially east and north of the Black Hills. ra/sn is expected with mostly snow in near KD07, but patchy freezing rain may occur this morning. Areas of MVFR/IFR conditions are expected through the period as additional low level moisture develops and in association with precipitation. Latest probabilistic guidance suggests upslope flow after 02/06z may lead to LIFR stratus/fog east of the Black Hills with later terminals for KRAP assessing the potential.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Winter Weather Advisory until noon MDT Thursday for SDZ002-014- 078. WY...None.